Sampling switch



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SAMPLING SWITCH Filed Sept. 2, 1958 4 51 1 51 1 FIC-kl- INVEN TOR.

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SAMPLING SWITCH Filed. Sept. 2, 1958 4 Sheets-Sheet 5 [N V EN TOR:

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SAMPLING SWITCH Filed Sept. 2, 1958 4 Sheets-Sheet 4 IN V EN TOR. Jaim 22 Glass,

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United States Patent 3,035,129 SAMPLRNG SWITCH John P. Glass, Ardmore, Pa. Filed Sept. 2, 1958, Ser. No. 753,503 6 (Iiaims. (Cl. 20tl38) This invention relates to improvements in electrical switches, and more particularly concerns improvements in sampling switch apparatus and with the armature apparatus thereof.

It is an object of this invention to provide sampling switch apparatus having switch contacts, the making and breaking of which are accurately timed and controlled.

It is another object of this invention to provide sampling switch apparatus having switch contacts which are fixedly secured against all unwanted movement including sliding and twisting movements.

It is another object of this invention to provide sampling switch apparatus having switch contacts fixedly secured to a support without the use of screws.

It is another object of this invention to provide sampling switch apparatus having switch contacts connected to electrical circuits wherein the exact sequence of opening and closing those circuits is accurately controlled.

It is another object of this invention to provide sampling switch apparatus having switch contacts connected to electrical circuits and wherein the exact sequence of opening and closing the circuits is easily adjustable.

It is another object of this invention to provide sampling switch apparatus which is quickly and easily replaceable as a package unit.

Other objects and advantages of this invention will further become apparent hereinafter and in the drawings, in which:

FIG. 1 is a view in side elevation and partly broken away of sampling switch apparatus constructed in accordance with this invention;

FIG. 2 is an enlarged view in section of a sampling switch constructed in accordance with this invention;

FIG. 3 is a View in section and partly broken away taken as indicated by the lines and arrows IIIHI which appear in FIG. 2;

FIG. 4 is an exploded view of the parts of the sampling switch;

FIG. 5 is a view in top plan and partly broken away of one embodiment of drive mechanism constructed in accordance with this invention;

FIG. 6 is a sectional view in elevation taken as indicated by the lines and arrows VIVI which appear in FIG. 5;

FIG. 7 is a view taken as indicated by the lines and arrows VII-VII which appear in FIG. 6;

FIG. 8 is a view in perspective of the trigger element of the drive mechanism; and

FIG. 9 is a partial View showing a modification of the cam element of the sampling switch.

Although specific terms are used in the following de scription for clarity, these terms are intended to refer only to the structure shown in the drawings and are not intended to define or limit the scope of the invention.

Turning now to the specific embodiment of the invention selected for illustration in the drawings, the number 11 designates generally a sampling switch apparatus including a casing 12 having mounted therein a timing motor 13, drive mechanism 14 with top plate 19 and bottom plate 24, sampling switches 15 and 16 having terminals 17, and terminal block 18 having casing terminals 22 (including prongs 21) which are connected by elec trical Wiring to terminals 17.

Referring to FIG. 2-4, sampling switch 15 is driven by drive shaft 23 which extends through bottom plate 24 of drive mechanism 14 and is keyed to a splined shaft 25 having an odd number of teeth 26. Mounted on shaft 25 are a number of rotatable cams 27a, b, c, and d. Cams 27 are provided with the same number of teeth 28 as splined shaft 25, and are provided with cam lobes 31a, b, c, and d. Splined shaft 25 may be of any desired length any number of cams 27 may be placed on splined shaft 25 to form a cam stack 32 of any desired length.

Positioned around cam stack 32 and concentric therewith is a stack 33 of support rings 34ad. Rings 34 are separated from each other by insulating washers 35.

Each ring 35 has formed therein a number of Z-shaped recesses 36 which are provided with Z-shaped inserts 37. Fixedly secured within each ring 34 is a flight of radially spaced cam followers 38 which are of fiat-leaf, spring construction and which are accurately machined as to dimensions. Also fixedly supported within recesses 36 are elongated contacts 41 which are provided with stop flanges 42 and contact pads 43. Contact pads 43 are adapted to make contact with contact pads 44 of cam follower 38. Also provided are bracket 45 and contact terminal bar 46.

In operation, timing motor 13 rotates to operate the drive mechanism 14 which rotates splined shaft 25 of the sampling switches 15 and 16. Rotation of splined shaft 25 causes the rotation of cams 2'7, and the cam lobes 31 actuate cam followers 38 so that contact pads 44 make contact with contacts 41 in a precisely controlled timing relation with each other. This timing relationship is shown in FIG. 3 which shows cam lobe 310 of cam 27c making contact with a cam follower 38 which is positioned away from a cam follower 33 mounted in ring 341; which is being contacted by lobe 31b of cam 27b.

The provision of an odd number of teeth on splined shaft 25 and on cams 27 permits accurate adjustment of the lobe position of the cams 27 relative to each other. For example, with 13 teeth provided as shown in the drawings, each tooth is separated from an adjacent tooth by an angle of approximately 2.3 degrees. Adjustment in the timing between cams 27 is accordingly very easily affected by removing, for example, cam 27d and rotating it one tooth and dropping it into the next slot of splined shaft 25. By removing cams 2'7 and replacing them in the appropriate slots, the time of closing the flight of cam followers 38 on ring 34a, for example, is adjusted with respect to the time of closing the flight of cam followers 38 on ring 3412. This provision of an odd number of teeth on splined shaft 25 and cams 27 provides for adjusting the radial position of lobe 31 of one cam 27 with respect to lobe 31 of another cam 27.

FIG. 9 shows another embodiment of a cam 47 which is provided with two lobes 48, 49.

Referring now to FIGS. 5-8, there is shown an alternate embodiment of the drive mechanism 52 which is located between the timing motor 13 and the sampling switch 15. Drive mechanism 52 rotates shaft 25 intermittently and is a delayed action drive, a snap action drive instead of a continuous one.

Timing motor 13 is connected either directly or through intermediate gearing to shaft 53 and gear 54. Gear 54 drives a gear 55 which is mounted free on a drive shaft 56 which is connected to and drives the splined shaft 25.

Drive shaft 56 has a collar 57 pinned thereto. Drive shaft 56 and gear 55 are operatively connected together through a spring 58 which has one end anchored in collar 57 and the other end anchored in gear 55.

Gear 55 has a stud 61 depending therefrom which acts to release the trigger mechanism hereinafter described.

Mounted on shaft 56 below gear 55 is a disc 62 having a slot 63 formed therein in which travels the stud 61.

Below disc 62 is positioned a trigger spring 64 having a pin 65 which is rotatably mounted in disc 62. Trigger spring 64 is also provided with a cam follower 66 and with a trigger release slot 67 which receives stud 61 and thus rotates trigger spring 64 so that earn follower 66 clears projections 68 of stationary cam 69.

FIG. 5 shows drive mechanism 52 in its uncooked position with drive shaft 56 prevented from rotation through the action of trigger spring 64 which is held by cam 69. This holds stationary the pin 65 of trigger spring 64 which in turn prevents from rotation the disc 62. As gear 55 rotates, it causes stud 61 to assume the position shown in FIG. 7, and causes trigger spring 64 to rotate so that cam follower 66 clears protuberance 68 of cam 69. Cam follower 66 being clear of cam 69, disc 62 is rapidly rotated a number of degrees through the action of spring 58.

The cocked position of trigger 54 is shown in FIG. 7 in solid lines, while the next uncocked position of trigger spring 64 is shown in FIG. 7 in dot-dash lines.

In operation, timing motor 13 rotates drive mechanism 52 by rotating shaft 53 and gear 54, which in turn rotates gear 55. Rotation of gear 55 winds up spring 58 and at the same time, through the rotation of stud 61., releases trigger spring 64. After trigger spring 64 is released, the spring 58 releases to rotate disc 62 a number of degrees of rotation and thereby rotate splined shaft 25.

The cam followers 38 of the sampling switch apparatus of this invention are made of flat-leaf spring construction and are accurately dimensioned to insure that the making and breaking of the cam followers 38 are accurately timed and controlled. The cam followers 33 are fixedly secured against all unwanted movement, including sliding and twisting movements, through the action of the Z-shaped recesses 36 and inserts 37, and this fixed anchorage is obtained without the use of screws. The exact sequence of opening and closing the electrical circuits which are connected to cam followers 38 is accurately controlled and is easily adjusted through the provision of an odd number of teeth on splined shaft 25 and carns 27. The entire apparatus is made as a package unit, as shown in FIG. 1, which is quickly and easily replaceable.

It is to be understood that the form of the invention herein shown and described is to be taken as a preferred embodiment. Various changes may be made in the shape, size and arrangement of parts. Equivalent elements may be substituted for those described herein, parts may be reversed, and certain features of the invention may be utilized independently of the use of other features, all without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. Sampling switch apparatus which is easily replaceable as a package unit, comprising a casing provided with electrical terminals mounted thereon accessible from the exterior of the casing, a timing motor mounted inside the casing, a splined shaft rotatably mounted within said casing and rotatable by said motor, a switch-contact support ring positioned around said splined shaft and radially spaced therefrom, said ring having a plurality of Z-shaped recesses formed therein, a plurality of circumferentially spaced apart switches mounted on said ring, each switch having a cam following contact and a non-cam following contact, said contacts having a Z-shaped portion mounted in said Z-shaped recesses to accurately determine the length of said contacts extending inwardly of said ring, a Z-shaped insert positioned between said contacts in said recesses for preventing any unwanted movement of said contacts including unwanted sliding and twisting, a rotatable cam mounted on said splined shaft for successively closing and opening each switch as said cam rotates, and electrical leads connecting said switch contacts to said electrical terminals.

2. Sampling switch apparatus comprising a splined shaft, a rotatable cam mounted on said splined shaft, a

switch-contact support ring positioned around said rotatable cam and radially spaced therefrom, said ring having a plurality of Z-shaped recesses formed therein, a plurality of circumferentially spaced apart switches mounted on said ring, each switch having a cam following contact and a non-cam following contact, said contacts having a Z-shaped portion mounted in said recesses to accurately determine the length of said contacts extending inwardly of said ring, and an insert positioned between said contacts in said recesses for preventing any unwanted movement of said contacts including unwanted sliding and twisting, whereby said contacts are successively closed and opened in response to the rotation of said cam.

3. The sampling switch apparatus defined in claim 2, wherein drive means are provided for intermittently driving said splined shaft and said cam.

4. Sampling switch apparatus comprising a splined shaft, a rotatable cam mounted on said splined shaft, a switch-contact support ring positioned around said rotatable cam and radially spaced therefrom, a plurality of circumferentially spaced apart switches mounted on said ring, each switch having a cam following contact and a non-cam following contact whereby said contacts are successively closed and opened in response to the rotation of said cam, a drive shaft connected to and extending axially from said splined shaft, a drive gear freely mounted on said drive shaft, a collar fixedly mounted on said drive shaft and rotatable therewith, a helical spring connected between said drive gear and said collar so that rotation of said drive gear winds up the spring when said collar is prevented from rotating, a disc fixedly mounted on said drive shaft below said drive gear, a stationary cam mounted below said disc and spaced radially from said drive shaft, trigger spring means connected between said disc and said stationary cam for preventing rotation of said cam, and stud means connected between said drive gear and said trigger spring means for releasing said trigger spring means and thereby releasing said helical spring to rotate said collar, drive shaft, and splined shaft.

5. Insampling switch apparatus, a switch-contact support ring, said ring having Z-shaped recesses formed in its top surface with said recesses being defined by Z-shaped shoulders, a fiat-leaf elongated contact having a Z-shaped portion positioned against one of said Z-shaped shoulders to accurately determine the length of said contact extending inwardly of said ring, another flat-leaf elongated contact having a Z-shaped portion positioned against the other of said Z-shaped shoulders to accurately determine the length of said contact extending inwardly of said ring, and a Z-shaped insert positioned between said contacts and said shoulders for preventing any unwanted movement of said contacts including unwanted sliding and twisting whereby the position of the inward ends of said contacts are accurately controlled in relation to said ring.

6. The apparatus defined in claim 5, wherein an elongated terminal bar is positioned between said other contact and said other Z-shaped shoulder, and a stop flange extends from said other contact to connect with terminal bar to limit the movement of said other contact therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 1,493,038 Huseth et a1. May 6, 1924 1,499,829 Kreutzer et a1. July 1, 1924 1,704,625 Nero Mar. 5, 1929 2,202,698 Latta May 28, 1940 2,219,372 Poole Oct. 29, 1940 2,262,306 Thompson et al. Nov. 11, 1941 2,547,999 Brockway Apr. 10, 1951 2,703,347 Constantine Mar. 1, 1955 2,711,448 Shewrnon et a1 June 21, 1955 2,795,658 Ward June 11, 1957 2,796,474 Glogan June 18, 1957 2,847,525 Everard Aug. 12, 1958 

